1. Field of the Invention
The present invention relates to an improved pump and nozzle for a fluid dispensing apparatus, more specifically, a collapsible cavity pump with an improved outflow valve assembly having an less restricted fluid flow path and greater area of flow capacity through the pump tip.
2. Background Art
Liquid and semi-liquid dispensers are used in numerous applications and are used to dispense metered portions of creams, lotions, soaps, and similar materials. A typical dispenser allows the user to obtain a specific amount of liquid matter with minimal ease. Manual and automatic dispensing systems are common in the industry.
Manual dispensers generally utilize levers and other mechanical assemblies wherein the user must provide some physical contact with the dispensing unit in order to expel a unit of liquid. Automatic dispensers are becoming increasingly popular, and operate with a variety of electrical and electro-mechanical components to automatically dispense the liquid after triggering some sensory input. Once the sensor mechanism is triggered, a mechanical means is still required to force out a metered quantity of liquid.
Within the field of liquid dispensers, there are many types of dispensers. The most common and cost effective is the bag-in-box system, where the liquid comes in a disposable no-leak pouch or bag, to which is fused a pump and outflow tip. This system is a closed system; all air is removed from the pouch during manufacturing. This helps prevent contamination of the soap supply. The bag collapses upon itself as the liquid is consumed, and when empty, the bag and pump are disposed of and replaced by a new one. The closed system has many advantages, including convenience and better sanitation. Several size pouches are common, including 800 ml, 1000 ml and 1200 ml; the size requirement being dictated by the size and capacity of the dispenser in which it is to be used.
It is a necessary requirement that the cost to produce a bag-in-box system be kept to a minimum, while still delivering consistently reliable performance. Soap dispensers are commonly installed in public facilities and are subject to extreme wear and tear, thus they must also be robust and relatively maintenance-free. As a disposable element of the system, a malfunctioning or defective bag and pump are simply discarded, along with any remaining liquid soap in the bag.
Other dispensers use cartridges or refillable containers. The cartridges must be pierced, are generally not refillable, and produce greater waste. Both cartridges and re-fillable containers introduce air into the system, aiding the production of bacteria and mold. The cost and administrative complexity in using these other forms of dispensers, as well as the decreased sanitary condition limits their market appeal. Regardless of the type of housing for the liquid, whether pouch, canister, cartridge or container, the liquid must still be dispensed through a dispenser valve assembly.
The liquid soap industry has numerous brands and categories of soaps. The viscosity and particulate content are also subject to extreme variations. There is an array of particulate matter that can be added to liquid soaps to form a grit soap compound that is more effective in cleaning. The most common grit material is plastic microspheres, although other materials such as clay, walnut shells and corn cobs have also been used. Besides the variations of compounds used to form grit soap, the size of the grit also varies.
There are several lines of liquid soaps with synthetic particles, namely plastic balls, that constitute grit compounds. The size of the particulate varies, and a series of products include Microgrit 40, Microgrit 60, and Microgrit 70. The increased consumer demand for grit in liquid soaps has led to an increase in malfunctions in existing dispensers.
There has also been a consumer demand for antimicrobial soaps, and the industry has reacted by adding creating new compounds with anti-bacterial properties. These antimicrobial soaps are available with or without grit and have certain characteristics and viscosity differences as compared to standard liquid soap.
Besides liquid soap, other compounds that are used in liquid dispensers include body and hair shampoo, hand cream solutions, lotion soaps, and shaving cream. Any flowable liquid is capable of being dispensed. Prior art designs are generally not effective in dispensing viscous liquids.
In a typical bag-in-box operation, a user depresses a lever or controller. This applies pressure to the liquid in the collapsible pouch that exerts fluid pressure against the ball in the ball check valve. If the pressure is sufficient, the ball is displaced, and the liquid flows around the ball and into the ball check valve chamber. The liquid flows into the space between the spring and the interior wall of the ball check valve chamber. Once the chamber is sufficiently full, the liquid is forced through the compressed spring and out through the lower fitment hole and through the nozzle.
Many of the current dispensers cannot adequately handle the grit, grit compounds, or viscous liquids. The dispenser valves have a narrow point or restricted passage that limits the size of the particulate matter that can pass freely and generally impedes viscous liquids. In most cases, this narrow area is directly before the exit nozzle, at the spring seat.
A common problem with most bag-in-box dispensers is that the dispenser valve tends to clog and become unusable after a number of manipulations. Once the pump tip becomes clogged, the entire pouch and pump tip is normally thrown out, regardless of the amount of liquid remaining in the pouch. The expenditure in time and materials is significant due to the number of dispensers in the market.
In order to reduce the aforementioned problems, attempts have been made to produce an efficient and cost-effective dispensing system. The prior art systems have general short-comings and do not adequately address or correct these problems.
The pump tip in U.S. Pat. No. 5,501,372 is an improved tip design, but as shown in FIG. 5, the liquid has a limited exit point that restricts the liquid flow. The spring contacts the flush spring seat, creating a bottleneck in the dispensing process. The liquid is substantially forced through the center of the spring in order to exit out of the nozzle tip. In addition, the flat surface of the spring seat provides a surface for collecting debris and otherwise facilitating clogging of the nozzle, especially when particulate matter is mixed with the liquid.
U.S. Pat. No. 4,130,224 is another dispensing apparatus, wherein the ball check valve is held in place by a spring, with the spring seat perpendicular to the spring, as illustrated in FIGS. 3, 4, 5, and 6. When the lever is pressed, the fluid is compressed, creating a pressure that exceeds the spring tension. The ball is forced away from the ball seat and fluid flows around the ball and into the inner chamber. The exit nozzle is smaller in dimension than the diameter of the inner chamber, and the spring seat is on the upper end of the exit nozzle, with the spring contacting the spring seat. The liquid must go through the spring to exit the nozzle.
A similar ball check valve is disclosed in FIG. 5 of U.S. Pat. No. 4,394,938 (""938), wherein the ""938 invention depicts the arrangement of the ball contacting the ball seat, and held in place by the spring. The spring is perpendicular to the spring seat, which is a substantially flat surface. When the ball is displaced from the ball seat, the liquid is forced around the ball. The path of the liquid is primarily down the cross sectional area outside the spring until the liquid contacts the flattened surface of the spring seat, where the liquid is then forced to exit through the center of the spring.
A similar ball check arrangement is shown in FIG. 10 of U.S. Pat. No. 4,515,294. The spring is retained within a tube, and a smaller diameter inner tube forms the lower end of the spring seat. Once the ball is displaced from the ball seat, the liquid flow is obstructed and must be diverted through the center of the spring before it enters the inner tube. In yet another dispenser device, U.S. Pat. No. 4,722,372 in FIG. 7 shows the spring seat flush and perpendicular to the spring as in previous examples.
U.S. Pat. No. 4,621,749 shows another ball check valve, where the lower end of spring chamber has a slight angle at the lower portion as shown in FIG. 10. However, the liquid must still flow around the spring in order to exit the cavity. In addition, the location of the angle is at a point where the flow is already restricted. Another example of an angled portion is shown U.S. Pat. No. 5,265,772 in FIG. 9. In both these figures, the bottom coil was not flat, but was angled like the other coils and seated in the chamber accordingly. Neither discloses nor suggests any significance relating to fluid flow characteristics, and neither discusses or infers any advantages to angled chamber design or elevated standoffs.
A different valve dispensing assembly is illustrated in U.S. Pat. No. 4,143,853, wherein a rubber disc with a slit is used as the means of gating the liquid flow. In operation, the normally closed slit is opened when a force is applied to the edges of the disc by the engaging assembly located on the outer periphery of the disc. In this invention, the planar seat surfaces are required in order to function properly. This invention is specifically intended for use as a catheter. U.S. Pat. No. 4,394,938 employs a similar design, wherein a slit diaphragm is used as the gating mechanism for dispensing metered portions.
Another design is disclosed in U.S. Pat. No. 4,607,764, where an elastomeric band functions as the check valve and allows a metered portion of liquid to be dispensed. This invention creates a flow channel by having specific openings and indents within which the fluid passes.
There remains a problem in the art with respect to a dispenser pump and tip design that eliminates the restriction and obstructions to the flow of particulate-ladened or heavily viscous liquid flow.
Many of the pump systems in the art utilize a collapsible hose, the upper and lower ends of which are equipped with an inflow and outflow check valve. A press bar is pressed against the hose, collapsing the hose and expelling a unit measure of liquid soap out the outflow into the user""s hands. When the press bar is relaxed, the hose recovers its normal shape and volume, refilling itself with liquid soap through the inflow check valve from the bag of soap to which it is attached.
A further development of the bag-in-a-box system has been the adaptation of collapsible bulb pumps, as is evident in the prior art GoJo NXT(trademark) and the Sterisol System 2000(trademark) liquid soap dispensing systems. Each uses a semi-spherical collapsible bubble, bulb or dome mounted on a backplate, which is fused to a disposable bag of liquid soap. The backplate incorporates an inflow check valve communicating with the bag, and an outflow check valve and pump tip from which soap is dispensed into the user""s hands. Depression and recovery of the bubble or dome, either by a press bar or directly by hand, performs the same function as the collapsing and recovery of the pump hose in the other prior art systems described above. The bag and bubble pump fit into their compatible dispensers in the same general manner as the bag and hose pump of the alternative systems. The prior comments about the addition of grit or particulate matter and other additives to liquid soap for improved scrubbing and cleaning performance apply to the soaps used in both hose pump and bubble pump systems.
Collapsible bubble, bulb and dome pumps are also represented in related fields, as demonstrated by Stern""s U.S. Pat. No. 5,452,826, issued Sep. 26, 1995, for a Proportioning Arrangement for Dispensing Portions of Liquid Foodstuff from a Foodstuff Container.
The invention, simply stated, is a pump for dispensing particulate-ladened or heavily viscous fluids such as grit-ladened or granulated hand soap or lotion, with a compressible pump cavity with an inlet and a streamlined outlet, and with a backflow check valve associated with the inlet and a nozzle assembly connected to the outlet. In the nozzle assembly, a spring loaded outflow ball valve resists outflow until sufficient fluid pressure is applied from within the pump cavity. A minimally flow restrictive spring base support structure holds the base of the spring apart from the nozzle tip, permitting fluid flow around the check ball and spring to the nozzle tip.
It is therefore an object of the invention to provide a collapsible bubble pump and tip design with a less restricted and greater cross sectional flow through the nozzle chamber into the outflow tip or nozzle. This eliminates the need for the fluid to be forced through check valve spring coils into the spring center to reach the nozzle, as in some prior art designs, and greatly increases the flow capacity of the dispenser. An additional objective of the invention is to provide a dispenser system with the ability to handle particulate-ladened and heavily viscous liquids, and to reduce the clogging evident in present designs. A yet further objective is to reduce the parts count of a soap pump and tip assembly. A still yet further objective of the invention is to combine the unibody construction of a bubble pump on a backplate with an improved flow pump tip for particulate-ladened and heavily viscous fluids.
Another additional object is to provide a streamlined flow path for the liquid flow from the pump cavity to the nozzle tip. Yet another object is to provide a soap pump with fewer obstructions or restrictions in the flow path through nozzle chamber by incorporating elevated standoffs for the spring seat. A still further object is to provide standoffs aligned with the direction of fluid flow so as to minimize fluid turbulence and direct the fluid flow out the nozzle tip.
Another object is to increase efficiency and reliability of soap dispensing systems by reducing the number of clogged dispensers. Most bag-in-box soap dispensers cannot be easily adjusted or repaired once the pump nozzle becomes clogged; and the bag and remaining soap must be thrown away along with the soap pump. The present invention possesses a high commercial value because it also significantly reduces the amount of wasted product and maintenance.
An additional object of the invention is to limit the clogging effect of the turns of the coil spring in the outflow check valves of the prior art on particulate-ladened or heavily viscous fluids.
An object of the invention is to provide a soap pump utilizing a collapsible, semi-spherical, resilient bubble mounted on a backplate having an inflow port and check valve attachable to a collapsible bag and an outflow port communicating with a dispensing nozzle. The nozzle has a check valve chamber with an inflow end and a dispensing tip end, a ball seat at the inflow end, a ball contacting the ball seat, and a coil spring within the chamber, one end of which urges the ball against the seat. The diameter of the coiled spring is sufficiently smaller than that of the chamber so as to provide a longitudinal fluid flow path in the ball seat, around the ball, and through the chamber external to the spring. There is within the chamber means for suspending the lower end of the coil spring in compression against the ball, elevated above the tip end of the chamber so that the fluid flow path does not require fluid to penetrate spring wall between the coils in order to reach the nozzle tip.
Another object is a soap pump as described above where the means of supporting the check valve spring is a plurality of uniformly distributed standoff legs or fins extending radially inward from the wall of the nozzle check valve chamber near the tip, each incorporating a notch or step which collectively function to retain the lower end of the coil spring in a centered position in the chamber. The legs would elevate and support the spring above the dispensing tip and provide a low drag profile to the fluid flow path passing from around the spring downward to the nozzle tip.
Yet a further object is a valve dispensing assembly, wherein the nozzle tip end of the chamber is funnel shaped. And yet another further object of the invention is to provide a rigid backplate diaphragm pump with improved fluid dynamics and reduced flow path resistance in the fluid flow path and valves.
Other objects, features and advantages are apparent from description in conjunction with the accompanying drawings.